Quantum Simulation

Quantum computers are the promising candidates for simulation of large quantum systems, which is a daunting task to perform in a classical computer. Here, we report the experimental realization of quantum tunneling of a single particle through different types of potential barriers by performing digital quantum simulations using IBM quantum computers. We consider two and three-qubit systems to visualize the tunneling process and illustrate its unique quantum nature. We observe the tunneling and oscillations of the particles in a step-well, double-well, and multi-well potentials through our experimental results. One may extend the proposed quantum circuits and simulation techniques used here for observing the tunneling phenomena for multi-particle systems in different potentials.

We design a quantum circuit in IBM quantum computer that mimics the dynamics of single photon in a coupled cavity system. By suitably choosing the gate parameters in the quantum circuit, we could transfer an unknown qubit state between the qubits. The condition for perfect state transfer is obtained by solving the unitary time dynamics governed by the Hamiltonian of the coupled cavity system. We then demonstrate the dynamics of entanglement between the two-qubits and show violation of Bell's inequality in IBM quantum computer.

Efficient simulation of quantum mechanical problems can be performed in a quantum computer where the interactions of qubits lead to the realization of various problems possessing quantum nature. Spin-Boson Model (SBM) is one of the striking models in quantum physics that enables to describe the dynamics of most of the two-level quantum systems through the bath of harmonic oscillators. Here we simulate the SBM and illustrate its applications in a biological system by designing appropriate quantum circuits for the Hamiltonian of photosynthetic reaction centers in IBM's 5-qubit quantum computer. We consider both two-level and four-level biomolecular quantum systems to observe the effect of quantum tunnelling in the reaction dynamics. We study the behaviour of tunneling by changing different parameters in the Hamiltonian of the system. The results of SBM can be applied to various two-, four- and multi-level quantum systems explicating electron transfer process.

We provide a method for (i) performing deterministic imaginary time evolution and (ii) computing the thermal average of gauge-invariant models. We assess scalability on quantum computers, employing a circuit-based formulation. We validate our framework by numerical simulations of two-and three-particle chains. Results show that the method is correct within a finitetemperature regime and may be used to approximate groundstate energies.

The monotonicity properties of quantum resource measures under restricted operations constitute fundamental constraints in quantum resource theory, yet rigorous proofs for many important measures have remained elusive. This paper provides the first complete solution to the stabilizer resource monotonicity problem by establishing that stabilizer Rényi entropies satisfy the monotonicity property for all under any stabilizer protocol (composed of Clifford unitaries, Pauli measurements, and classical post-processing). The proof employs a novel connection between stabilizer Rényi entropies and the Pauli spectrum of quantum states, combined with majorization theory and properties of Schur-concave functions. We demonstrate that this monotonicity is equivalent to a majorization relation on Pauli spectra, provide explicit computational algorithms for verification, and establish the optimality of the constraint through counterexamples for. Extensive numerical validation across 10,000 random protocols confirms the theoretical predictions with statistical significance. The results resolve a longstanding open problem in stabilizer quantum resource theory and provide new mathematical tools for analyzing nonstabilizer quantum resources. Applications to quantum algorithm complexity, error correction thresholds, and resource optimization protocols demonstrate the practical significance of these theoretical advances.

Este trabajo presenta una demostración rigurosa de la monotonicidad de entropías estabilizadoras S_α(ρ)= (1/(1-α))log(Tr(ρ^α)) para parámetros α ≥ 2 bajo transformaciones completamente positivas quepreservan la traza (CPTP) y mantienen la estructura del grupo estabilizador. Esta contribución resuelveuna pregunta teórica fundamental en la teoría cuántica de recursos que ha permanecido abierta durantevarios años. La demostración utiliza propiedades de convexidad de funciones, teoría de matrices, yanálisis funcional para establecer que estas entropías constituyen monótonas válidas de recursoscuánticos. Los resultados tienen implicaciones directas para la optimización de protocolos de correcciónde errores cuánticos, destilación de estados mágicos, y el desarrollo de límites fundamentales encomputación cuántica tolerante a fallos. Se proporcionan aplicaciones computacionales que demuestranmejoras del 15-20% en límites de conversión de recursos comparado con métodos existentes.

The Synthetic Amniotic Gel Flux Capacitor (SAGFluxCap) is a temporal metamaterial exhibiting negative group delay, pulse storage/release, and Floquet sideband formation. This white paper frames these results within a unified theoretical spectrum: nonlinear time theory, Pimensional spacetime (URF), quantum field theory (QFT), string theory, nonAbelian group theory, and the holographic principle. We formalize the Pimensional geometry as a fiber bundle, define resonance connections and Floquet monodromies, and demonstrate how sidebands correspond to vibrational string modes, SU(2)/SU(3) multiplets, and holographic boundary/bulk encodings. This positions SAGFluxCap as a laboratoryscale analogue of fundamental physics, with applications to communications, imaging, and quantum simulation.

Presently, the low power and high efficiency are imperishable problem in technological gadgets. With the emergence of technologies like 5G and others, it has become requisite to meet the challenge before peeved. In this paper we entrust FinFETs, and CNTFETs technologies which are found to be upbeat field of research. The paper presents the performance enhancements of CNTFETs at 14 nm node and discusses the important areas of their applications and future scope.

The nature of photon propagation remains a central question in both theoretical physics and ontological inquiry. Conventional models—particularly quantum field theory—describe photons as quanta of fields, propagating via probabilistic wave functions. However, this approach introduces conceptual tensions: if a photon “travels” as a material particle, it must interact with the medium, potentially altering its structure. This contradicts the notion of a photon as a stable, unchanging quantum.
This paper introduces an alternative framework: photon propagation as the sequential transmission of a locally generated process. Rather than treating the photon as a discrete object moving through space, we conceptualize it as a process initiated by a source and transmitted through a structured field. This model offers a more coherent ontological and physical explanation, emphasizing locality, determinism, and processual realism.

Large-scale quantum computers will inevitably need quantum error correction (QEC) to protect information against decoherence. Given that the overhead of such error correction is often formidable, autonomous quantum error correction (AQEC) proposals offer a promising near-term alternative. AQEC schemes work by transforming error states into excitations that can be efficiently removed through engineered dissipation. The recently proposed AQEC scheme by Li et al., called the Star code, can autonomously correct or suppress all single qubit error channels using two transmons as encoders with a tunable coupler and two lossy resonators as a cooling source. The Star code requires only two-photon interactions and can be realized with linear coupling elements, avoiding experimentally challenging higher-order terms needed in many other AQEC proposals, but needs carefully selected parameters to achieve quadratic improvements in logical states' lifetimes. Here, we theoretically and numerically demonstrate the optimal parameter choices in the Star Code. We further discuss adapting the Star code to other planar superconducting circuits, which offers a scalable alternative to single qubits for incorporation in larger quantum computers or error correction codes.

We give a general overview of the high-frequency regime in periodically driven systems and identify three distinct classes of driving protocols in which the infinite-frequency Floquet Hamiltonian is not equal to the time-averaged Hamiltonian. These classes cover systems, such as the Kapitza pendulum, the Harper-Hofstadter model of neutral atoms in a magnetic field, the Haldane Floquet Chern insulator and others. In all setups considered, we discuss both the infinite-frequency limit and the leading finite-frequency corrections to the Floquet Hamiltonian. We provide a short overview of Floquet theory focusing on the gauge structure associated with the choice of stroboscopic frame and the differences between stroboscopic and non-stroboscopic dynamics. In the latter case one has to work with dressed operators representing observables and a dressed density matrix. We also comment on the application of Floquet Theory to systems described by static Hamiltonians with well-separated energy scales and, in particular, discuss parallels between the inverse-frequency expansion and the Schrieffer-Wolff transformation extending the latter to driven systems.

Recently, it has been shown that the quantum spin-1/2 spin operators can be exactly transformed not only in spinless, but also in spinful canonical Fermi operators in 1D [1] and 2D [2] as well. In this paper, using the same technique based on an extended Jordan-Wigner transformation, we show in 1D that the quantum spin-1/2 operators can be exactly transformed also in spinful canonical Fermi operators of spin-1/2 fermions that are belong to two bands.

En este trabajo presentamos la Teoría Cuántica de Resonancia del Vacío (TCRV), una propuesta ontopológica que postula que el tiempo, el espacio y la materia emergen como estados resonantes del campo cuántico del vacío. A partir de una fase primordial previa al espacio-tiempo, se desarrolla un modelo de resonancia que da lugar a la estructura física del universo. El documento introduce ecuaciones fundamentales, postulados físicos, mecanismos de ruptura de fase, y simulaciones numéricas que modelan el nacimiento del espaciotiempo. Esta teoría busca aportar una visión unificada del origen del cosmos desde una perspectiva fásica-resonante.
Presenta las aplicaciones experimentales de la Teoría Cuántica de Resonancia del Vacío (TCRV). Se propone un modelo teórico-funcional para la extracción de energía del vacío a través del generador Helios Phase-1, basado en resonancia de fase cuántica. Además, se introduce el modelo Λ-Null como límite hipotético de ruptura fásica y se describen seis fases cosmológicas simulables, desde la oscilación primordial hasta el apagado coherente del universo. El texto integra ecuaciones, principios de seguridad y diseño conceptual de laboratorio, abriendo la posibilidad de validar aspectos de la TCRV en entornos experimentales controlados.

The properties of the solutions of the Klein-Gordon equations for various metrics of the general theory of relativity are considered. It is shown that the presence of singular points of the metric leads to qualitative rearrangement solutions of this equation, and the desingularization of solutions by the choice of a new metric requires a priori assumptions that can lead to formally mathematically correct results, albeit, with paradoxical physical meanings.

This redacted scientific whitepaper outlines the theoretical basis and symbolic simulation approach behind the Xenovium Project — a hypothesis-driven exploration of a potential superheavy element, Xenovium (Z=164). Using the AeonCore-X platform, the project blends symbolic AI, relativistic orbital models, and nuclear theory to simulate plausible atomic configurations and decay pathways beyond the current limits of synthesis. This version is optimized for research visibility and institutional review.

Prepared by Dr. Marios Efthymiou (Vision Architect, Xenovium Project / Director, IREDT)

Type-II fusion is a probabilistic entangling measurement that is essential to measurement-based linear optical quantum computing and can be used for quantum teleportation more broadly. However, it remains under-explored for high-dimensional qudits. Our main result gives a Type-II fusion protocol with proven success probability approximately 2/d^2 for qudits of arbitrary dimension d. This generalizes a previous method which only applied to even-dimensional qudits. We believe this protocol to be the most efficient known protocol for Type-II fusion, with the d=5 case beating the previous record by a factor of approximately 723. We discuss the construction of the required (d-2)-qudit ancillary state using a silicon spin qudit ancilla coupled to a microwave cavity through time-bin multiplexing. We then introduce a general framework of extra-dimensional corrections, a natural technique in linear optics that can be used to non-deterministically correct non-maximally-entangled projections into Bell measurements. We use this method to analyze and improve several different circuits for high-dimensional Type-II fusion and compare their benefits and drawbacks.

I propose a theoretical framework that integrates quantum entanglement, golden-ratio harmonic structures, and topological field dynamics into a unified model of quantum mechanics which I will demonstrate with an A.I designed quantum-fractal holographic simulation framework called the Platonic Light Matrix. This model conceptualizes a quantum-coherent field capable of real-time non-local interaction, protective stabilization, and holographic encoding. Central to the model is a Lagrangian density incorporating scalar-gauge-spinor couplings modulated by ϕ-based harmonics, Wilson loop topologies, and error-correcting entanglement networks. We explore implications for quantum protection systems, non-local sensing technologies, and quantum metamaterials. A multi-scale visualization method is outlined to simulate the field dynamics interactively.

This paper presents an in-depth exploration of cutting-edge theoretical frameworks that aim to redefine our understanding of the fundamental structure of reality, specifically concerning space and time. Examining key concepts such as gravity as thermodynamics, loop quantum gravity, causal sets, causal dynamical triangulations, and holography, this analysis integrates contemporary insights from quantum physics, cosmology, and mathematical physics. By exploring these varied yet interconnected theories, the paper illuminates potential paths toward a unified description of reality, bridging quantum mechanics and general relativity, and profoundly impacting our conception of the cosmos.

and my good friends, Yu-Miin Sheu and Jia-Yin Chao, for their support and companionship during these years in Ann Arbor. I cherish every opportunity to interact with them and benefit a lot from their valuable opinions and advice. I would especially like to thank Wei Yi, who helped me familiarize myself with the subjects of study when I first came to the group (including helping publish my first paper), Wei Zhang, who shared lots of his experiences and inspired me in many ways, and Jason Kestner, who has been not only my classmate and a smart collaborator but also a best friend during these years. I appreciate his friendship and understanding in all aspects; through him I iii see only positive attitudes for being an enthusiastic researcher and also a civilized person.

Interference with atomic and molecular matter waves is a rich branch of atomic physics and quantum optics. It started with atom diffraction from crystal surfaces and the separated oscillatory fields technique used in atomic clocks. Atom interferometry is now reaching maturity as a powerful art with many applications in modern science. In this review the basic tools for coherent atom optics are described including diffraction by nanostructures and laser light, three-grating interferometers, and double wells on atom chips. Scientific advances in a broad range of fields that have resulted from the application of atom interferometers are reviewed. These are grouped in three categories: ͑i͒ fundamental quantum science, ͑ii͒ precision metrology, and ͑iii͒ atomic and molecular physics. Although some experiments with Bose-Einstein condensates are included, the focus of the review is on linear matter wave optics, i.e., phenomena where each single atom interferes with itself.

Recent cold atom experiments have realized models where each hyperfine state at an optical lattice site can be regarded as a separate site in a synthetic dimension. In such synthetic ribbon configurations, manipulation of the transitions between the hyperfine levels provide direct control of the hopping in the synthetic dimension. This effect was used to simulate a magnetic field through the ribbon. Precise control over the hopping matrix elements in the synthetic dimension makes it possible to change this artificial magnetic field much faster than the time scales associated with atomic motion in the lattice. In this paper, we consider such a magnetic flux quench scenario in synthetic dimensions. Sudden changes have not been considered for real magnetic fields as such changes in a conducting system would result in large induced currents. Hence, we first study the difference between a time varying real magnetic field and an artificial magnetic field using a minimal six site model. This minimal model clearly shows the connection between gauge dependence and the lack of on site induced scalar potential terms. We then investigate the dynamics of a wavepacket in an infinite two or three leg ladder following a flux quench and find that the gauge choice has a dramatic effect on the packet dynamics. Specifically, a wavepacket splits into a number of smaller packets moving with different velocities. Both the weights and the number of packets depend on the implemented gauge. If an initial packet, prepared under zero flux in a n-leg ladder, is quenched to Hamiltonian with a vector potential parallel to the ladder; it splits into at most n smaller wavepackets. The same initial wavepacket splits into up to n 2 packets if the vector potential is implemented to be along the rungs. Even a trivial difference in the gauge choice such as the addition of a constant to the vector potential produces observable effects. We also calculate the packet weights for arbitrary initial and final fluxes. Finally, we show that edge states in a thick ribbon are robust under the quench only when the same gap supports an edge state for the final Hamiltonian.

Quantum phases of the Rabi lattice in the dispersive regime GUANYU ZHU, Northwestern University, SEBASTIAN SCHMIDT, ETH Zurich, JENS KOCH, Northwestern University -Photon-based strongly correlated lattice models like the Jaynes-Cummings and Rabi lattices differ from their more conventional relatives like the Bose-Hubbard model by the presence of an additional tunable parameter: the frequency detuning between the pseudo-spin degree of freedom and the harmonic mode frequency on each site. Whenever this detuning is large compared to relevant coupling strengths, the system is said to be in the dispersive regime. The physics of this regime is well-understood at the level of a single Jaynes-Cummings or Rabi site, and can be realized in circuit-QED architecture. Here, we extend the theoretical description of the dispersive regime to lattices with many sites, for both strong and ultra-strong coupling. We discuss the nature and spatial range of the resulting qubit-qubit and photon-photon coupling. In the ultra-strong coupling regime, we demonstrate the emergence of the paramagnetic-to-ferromagnetic phase transition of photon-dressed qubits in the negative detuning regime, and the photon-pairing and vacuum squeezing in the positive detuning regime. We illustrate our results by exact diagonalization of the Rabi dimer.

Periodically driving a quantum system can generate phases of matter without analog in stationary systems. Discrete time crystals (DTCs) are one such case, where the spontaneous breaking of a time translational symmetry is forbidden in the time-independent case. Previous observations of this effect relied on strong disorder to stabilize the discrete time crystal's temporal oscillations. Here, we report on the generation of DTC like behavior in a disorderless regime over finite length prethermal timescales. A 1D chain of up to 30 trapped ions is used to simulate a periodically driven long-range interacting spin model, with an individual addressing laser to prepare arbitrary initial spin configurations. The stability of the prethermal time crystal regime is probed by varying the drive frequency and choosing different initial states with varying energy densities. We observe that both low frequency drives and high energy density initial states destroy the periodic time dynamics. Moreover, the single site resolution of this experiment allows us to confirm that the motion of individual domain walls contributes to the decay of the spin order.

An exact Jordan-Wigner type of transformation is presented in 1D connecting
spin-1/2 operators to spinful canonical Fermi operators. The transformation
contains two free parameters allowing a broad interconnection possibility in
between spin models and fermionic models containing spinful Fermi operators.

Single particle interference experiments have documented the existence of trajectory of particles' during the accumulation of an interference pattern. The expression for probability of particle's arrivals to the screen was derived previously [22] by approximating the trajectories with straight lines, which start at various points of the slits, and using wave function of the transverse motion in the momentum representation. We use this expression to determine particle distribution at various distances along the lines parallel to a multiple slit grating. The agreement with usual probability density given by the modulus square of the wave function in coordinate representation is very good in the far field. In the near field the agreement is poor. This result supports the view that the trajectories of the particles do exist and that they are straight lines in the far fields, but further study on the form of the trajectories of particles' in the near field is necessary.

This work introduces an approach to quantum simulation by leveraging continuous-variable systems within a photonic hardware-inspired framework. The primary focus is on simulating static properties of the ground state of Hamiltonians associated with infinite-dimensional systems, such as those arising in quantum field theory. We present a continuous-variable variational quantum eigensolver compatible with state-of-the-art photonic technology. The framework we introduce allows us to compare discrete and continuous variable systems without introducing a truncation of the Hilbert space, opening the possibility to investigate the scenarios where one of the two formalisms performs better. We apply it to the study of static properties of the Bose-Hubbard model and demonstrate its effectiveness and practicality, highlighting the potential of continuous-variable quantum simulations in addressing complex problems in quantum physics.

We present a detailed study of the topological Schwinger model [Phys. Rev. D 99, 014503 (2019)], which describes (1+1) quantum electrodynamics of an Abelian U(1) gauge field coupled to a symmetry-protected topological matter sector, by means of a class of Z N lattice gauge theories. Employing density-matrix renormalization group techniques that exactly implement Gauss' law, we show that these models host a correlated topological phase for different values of N, where fermion correlations arise through inter-particle interactions mediated by the gauge field. Moreover, by a careful finite-size scaling, we show that this phase is stable in the large-N limit, and that the phase boundaries are in accordance to bosonization predictions of the U(1) topological Schwinger model. Our results demonstrate that Z N finite-dimensional gauge groups offer a practical route for an efficient classical simulation of equilibrium properties of electromagnetism with topological fermions. Additionally, we describe a scheme for the quantum simulation of a topological Schwinger model exploiting spin-changing collisions in boson-fermion mixtures of ultra-cold atoms in optical lattices. Although technically challenging, this quantum simulation would provide an alternative to classical density-matrix renormalization group techniques, providing also an efficient route to explore real-time non-equilibrium phenomena.

The interplay of symmetry, topology, and many-body effects in the classification of phases of matter poses a formidable challenge in condensed-matter physics. Such many-body effects are typically induced by interparticle interactions involving an action at a distance, such as the Coulomb interaction between electrons in a symmetry-protected topological (SPT) phase. In this work we show that similar phenomena also occur in certain relativistic theories with interactions mediated by gauge bosons, and constrained by gauge symmetry. In particular, we introduce a variant of the Schwinger model or quantum electrodynamics (QED) in 1+1 dimensions on an interval, which displays dynamical edge states localized on the boundary. We show that the system hosts SPT phases with a dynamical contribution to the vacuum θ-angle from edge states, leading to a new type of topological QED in 1+1 dimensions. The resulting system displays an SPT phase which can be viewed as a correlated version of the Su-Schrieffer-Heeger topological insulator for polyacetylene due to non-zero gauge couplings. We use bosonization and density-matrix renormalization group techniques to reveal the detailed phase diagram, which can further be explored in experiments of ultra-cold atoms in optical lattices.

We propose a quantum algorithm for projecting a quantum system to eigenstates of any Hermitian operator, provided one can access the associated control-unitary evolution for the ancilla and the system, as well as the measurement of the controlling ancillary qubit. Such a Hadamard-test like primitive is iterated so as to achieve the spectral projection, and the distribution of the projected eigenstates obeys the Born rule. This algorithm can be used as a subroutine in the quantum annealing procedure by measurement to drive the system to the ground state of a final Hamiltonian, and we simulate this for quantum many-body spin chains.

Quantum computing has the potential to revolutionize computing for certain classes of problems with exponential scaling, and yet this potential is accompanied by significant sensitivity to noise, requiring sophisticated error correction and mitigation strategies. Here we simulate the relaxations of stationary states at different frequencies on several quantum computers to obtain unique spectroscopic fingerprints of their noise. Response functions generated from the data reveal a clear signature of non-Markovian dynamics, demonstrating that each of the quantum computers acts as a non-Markovian bath with a unique colored noise profile. The study suggest that noisy intermediatescale quantum computers (NISQ) provide a built-in noisy bath that can be analyzed from their simulation of closed quantum systems with the results potentially being harnessed for error mitigation or open-system simulation.

The exact solution of Schrödinger equation for atoms, molecules and extended systems continues to be a "Holy Grail" problem that the entire field has been striving to solve since its inception. Recently, breakthroughs have been made in the development of quantum annealing and coherent Ising machines capable of simulating hundreds of connected spins interacting with an Ising type Hamiltonian. One of the most vital questions pertaining to these new devices is: 'can these machine be used to perform electronic structure calculations?' Here we discuss the general procedure used by these devices and show that there is an exact mapping between the electronic structure Hamiltonian of the Hydrogen molecule and the Ising Hamiltonian.

A method of rare event simulation, termed here quantum simulation, and known also (with some variations) as population Monte Carlo, and Sequential Markov Chain simulation, is applied in this paper to rare event simulation of communication systems. The technique described in this paper generalizes importance sampling, importance splitting and the Monte Carlo method which uses a collection (population) of particles. The term quantum simulation is used for the rare-event simulation technique presented in this paper because the entire ensemble of simulations resembles the parallel universes model of quantum mechanics. By using cloning, thinning and distortion it is possible to design simulations with the speed of importance sampling and the flexibility of importance splitting. A particularly difficult system is investigated in this paper by means of quantum simulation, namely a buffer fed by a Poisson-Pareto Burst Process. The simulations are able to confirm an analytic approximation for this model to a degree not previously achievable. Furthermore, this approximation was originally developed as a consequence of the investigation of this model by means of quantum simulation.

The bulk-edge correspondence in topological phases is extended to systems with the generalized chiral symmetry, where the conventional chiral symmetry is broken. In such systems, we find that the edge state exhibits an unconventional behavior in the presence of the symmetry breaking by the mass, which is explored explicitly in the case of a deformed Su-Schrieffer-Heeger model. The localization length of the edge states diverges at a certain critical mass, where the edge state touches the bulk band. The edge state is specified by an imaginary wave vector that becomes real at the touching energy.

Topological insulators are fascinating states of matter exhibiting protected edge states and robust quantized features in their bulk. Here, we propose and validate experimentally a method to detect topological properties in the bulk of one-dimensional chiral systems. We first introduce the mean chiral displacement, an observable that rapidly approaches a value proportional to the Zak phase during the free evolution of the system. Then we measure the Zak phase in a photonic quantum walk of twisted photons, by observing the mean chiral displacement in its bulk. Next, we measure the Zak phase in an alternative, inequivalent timeframe, and combine the two windings to characterize the full phase diagram of this Floquet system. Finally, we prove the robustness of the measure by introducing dynamical disorder in the system. This detection method is extremely general, and readily applicable to all present one-dimensional platforms simulating static or Floquet chiral systems.

Quantum simulation, a groundbreaking approach in the entire field of quantum science, allows the exploration and understanding of complex physical systems that are beyond the reach of our present classical computers. This article examines the advantages of quantum simulations, emphasizing the pivotal role that entanglement plays in achieving these stunning benefits. By delving deeper into the advanced theoretical concepts and practical applications, quantum simulation is shown to be reshaping the ability to model and solve problems in the fields ranging from materials science to significant branches of quantum chemistry. Insights/Intuitions into the future directions of quantum simulation research highlight how continued advancements may unlock transformative new possibilities and also address some of the most challenging and intriguing questions in science and technology to answer.

T his whitepaper is an outcome of the workshop Intersections between Nuclear Physics and Quantum Information held at Argonne National Laboratory on 28-30 March 2018. The workshop brought together 116 national and international experts in nuclear physics and quantum information science to explore opportunities for the two fields to collaborate on topics of interest to the U.S. Department of Energy (DOE) Office of Science, Office of Nuclear Physics, and more broadly to U.S. society and industry. The workshop consisted of 22 invited and 10 contributed talks, as well as three panel discussion sessions. Topics discussed included quantum computation, quantum simulation, quantum sensing, nuclear physics detectors, nuclear many-body problem, entanglement at collider energies, and lattice gauge theories.

Decoherence is a major challenge in quantum computing. To enable execution of quantum al- gorithms, it is crucial to eliminate decoherence and noise for instance via dynamic decoupling and quantum error correction protocols based on dynamic zero-noise strategy. As potential alternatives we introduced self-protected quantum algorithms over 15 years ago. Quantum algorithms of this kind, based on the living-with-noise strategy, are now used in the Noisy Intermediate-Scale Quan- tum regime. Here we introduce self-protected quantum simulations in the presence of weak classical noises. Notably, we prove the equivalence between weak classical noise and noiseless quantum sim- ulations. This equivalence implies that a self-protected quantum simulation does not require any extra overhead in its experimental implementation. Furthermore, we find that the conventional quantum phase estimation can be upgraded to its corresponding noisy version.

Topological insulators are fascinating states of matter exhibiting protected edge states and robust quantized features in their bulk. Here we propose and validate experimentally a method to detect topological properties in the bulk of one-dimensional chiral systems. We first introduce the mean chiral displacement, an observable that rapidly approaches a value proportional to the Zak phase during the free evolution of the system. Then we measure the Zak phase in a photonic quantum walk of twisted photons, by observing the mean chiral displacement in its bulk. Next, we measure the Zak phase in an alternative, inequivalent timeframe and combine the two windings to characterize the full phase diagram of this Floquet system. Finally, we prove the robustness of the measure by introducing dynamical disorder in the system. This detection method is extremely general and readily applicable to all present one-dimensional platforms simulating static or Floquet chiral systems.

We analytically designed the control bias pulses to realize new multi-qubit parity detector gates for 2-Dimensional (2D) array of superconducting flux qubits with non-tunable couplings. We designed two 5-qubit gates such that the middle qubit is the target qubit and all four coupled neighbors are the control qubits. These new gates detect the parity between two vertically/horizontally coupled neighbor qubits while cancelling out the coupling effect of horizontally/vertically coupled neighbor qubits. For a 3 by 3 array of 9 qubits with non-tunable couplings, we simulated the effect of our new 5-qubit horizontal and vertical parity detector gates. We achieved the intrinsic fidelity of 99.9% for horizontal and vertical parity detector gates. In this paper we realize Surface Code memories based on the multi-qubit parity detector gates for nearest neighbor superconducting flux qubits with and without tunable couplings. However, our scheme is applicable to other superconducting qubits as ...

We present a simplified analog quantum simulation protocol for preparing quantum states that embed solutions of parabolic partial differential equations, including the heat, Black-Scholes and Fokker-Planck equations. The key idea is to approximate the heat equations by a system of hyperbolic heat equations that involve only first-order differential operators. This scheme requires relatively simple interaction terms in the Hamiltonian, which are the electric and magnetic dipole moment-like interaction terms that would be present in a Jaynes-Cummings-like model. For a ddimensional problem, we show that it is much more appropriate to use a single d-level quantum system-a qudit-instead of its qubit counterpart, and d + 1 qumodes. The total resource cost is efficient in d and precision error, and has potential for realisability for instance in cavity and circuit QED systems.

Four-body interaction plays an important role in many-body systems, and it can exhibit interesting phase transition behaviors. Historically it was the need to efficiently simulate quantum systems that lead the idea of a quantum computer. In this Letter, we report the experimental demonstration of a four-body interaction in a four-qubit nuclear magnetic resonance quantum information processor. The strongly modulating pulse is used to implement spin selective excitation. The results show a good agreement between theory and experiment.

This thesis explores the application of Owens' Quantum Potential Framework in the real-time detection and analysis of neutrino physics. Using advanced quantum computing techniques, particularly the D-Wave quantum processing unit (QPU), we have simulated extensive neutrino oscillations and dynamics. This framework provides a novel approach to understanding the complex behavior of neutrinos, which are fundamental yet elusive particles in the Standard Model of particle physics. The results presented demonstrate the enhanced capabilities of quantum computing in tackling such high-dimensional and intricate problems, showcasing potential breakthroughs in the field of neutrino physics.

In this paper we study the polarized vacuum energy on the conducting surface of a topological insulator characterized by both Z2 topological index and time reversal symmetry. This boundary is subject to the action of a static and spatially homogeneous magnetic field perpendicular to it as well as of an electric field that is uniform near the considered surface and produced by a biased voltage, at zero temperature. To do this, we consider modifications in the Gauss law that arise due to the nonzero gradient of the axionlike pseudoscalar factor coupled to the applied magnetic field, which accounts for the topological properties of the system. Such a term allows us to find a correction to the induced charges which modifies the quantum vacuum of the spinor field regarding an ordinary surface. The polarized vacuum energy is calculated in both the weak-field approximation and in the general case, and since the found energy depends on a length defined on the boundary, we show that there is a radial density of force or a surface shear stress that tends to shrink it.

Recently, Panuski and Mungan presented the results of their study of light diffraction from a variablewidth single slit by observing and measuring the diffraction pattern on an observation screen placed at a fixed distance. In this way, the authors were able to demonstrate to students the important near-field effects for single slit diffraction which most often have been neglected in introductory courses. In this paper, we show that there exists very good agreement between observed data and theoretical calculations by plotting intensity from single slits using a method with Fresnel-Kirchhoff integrals (Fig. 2). In addition to these comparisons, and with the evaluation of Fresnel numbers, we argue that Panuski and Mungan demonstrated not only the near-field Fresnel, but also the far-field Fraunhofer regimes as well as the transition between the two. Furthermore, with a greater increase in the slit width, the transition to the geometric regime can be demonstrated (Fig. 3).

A simulator for quantum information systems cannot be both general, that is, easily used for every possible system, and efficient. Therefore, some systems will have aspects which can only be simulated by cunning modeling. On the other hand, a simulation may conveniently do extra-systemic processing that would be impractical in a real system. We illustrate with examples from our quantum computing simulator, QCSim. We model the [3,1] Hamming code in the presence of random bit flip or generalized amplitude damping noise, and calculate the expected result in one simulation run, as opposed to, say, a Monte Carlo simulation, and keep the original state to compute the chance of successful transmission, too. We also model the BB84 protocol with eavesdropping and random choice of basis and compute the chance of information received faithfully. Finally, we present our simulation of teleportation as an example of the trade-off between complexity of the simulation model and complexity of simulation inputs and as an example of modeling measurements and classical bits.